1. Field of the Invention
The present invention relates to an optical communication module and a connector equipped with this optical communication module. More specifically, it relates to an optical communication module for single-core bi-directional communication and the like.
2. Description of Related Art
FIG. 1 is an explanatory illustration of an outlined configuration of an optical communication system for performing single-core bi-directional optical-fiber communication. This optical communication system 100 has such a configuration that optical communication modules 101 wherein each module is equipped with a light-emitting element and a photoreceptor element, are connected to each other by one optical fiber 102. When data is transmitted from one of the optical communication modules 101A to the other optical communication module 101B, the light-emitting element of the optical communication module 101A emits transmitting light. The transmitting light emitted from the light-emitting element of the optical communication module 101A is transferred through the optical fiber 102 and then, the photoreceptor element of the other optical module 101B receives it.
When data is transmitted from the other optical communication module 101B to the one optical communication module 101A, the light-emitting element of the optical communication module 101B emits transmitting light. The transmitting light emitted from the light-emitting element of the optical communication module 101B is transferred through the optical fiber 102, which is also used to transmit data from the optical communication module 101A, and then, the photoreceptor element of the other optical module 101A receives it.
Such a technology is referred to as “single-core bi-directional communication” as to thus use the same optical fiber 102 both in a case where data is transmitted from the one optical communication module 101A and received by the other optical communication module 101B and in a case where data is transmitted from the other optical communication module 101B and received by the one optical communication module 101A. In particular, a technology for performing transmission and reception simultaneously is referred to as “single-core bi-directional full-duplex communication”.
It is to be noted that the optical communication module 101 for performing the single-core bi-directional communication needs to have a configuration to separate the transmitting light and the received light from each other. Conventionally, such a system is mainly used as to separate a polarized light peculiar to reflected light of the transmitting light using a beam splitter in order to separate the transmitting light and the received light from each other.
However, since the beam splitter is an expensive optical component, it is difficult to reduce costs of the communication module. Therefore, such a configuration has been suggested as to separate the transmitting light and the received light from each other using a reflecting mirror (see, for example, Japanese Patent Application Publication No. 2001-242354).
FIG. 2 is an outlined side view for showing a configuration of such a conventional optical communication module. A light-emitting element 103 is arranged along an optical axis of the optical fiber 102. Between this light-emitting element 103 and an end face of the optical fiber 102, a reflecting mirror 104 is arranged which has a transmission factor of about 50% and a reflection coefficient of about 50%. A photoreceptor element 105 is provided along a path of light reflected by the reflecting mirror 104.
In this configuration, transmitting light from the light-emitting element 103 passes through the reflecting mirror 104 and is made incident upon the optical fiber 102. Received light that has been emitted from the optical fiber 102, on the other hand, is reflected by the reflecting mirror 104 and made incident upon the photoreceptor element 105.
However, even if the configuration utilizes a reflecting mirror, it is difficult to miniaturize the optical communication module. In a case where use of an optical communication module for domestic appliances is premised, the module is required not only to be low in costs but also to be small in size. However, it is difficult to reduce costs and sizes of such a configuration as to use an optical component in order to separate optical paths, which has been a problem.